桁
コウ, けた
beam, girder, spar, unit or column (accounting)
JLPT0 G7 S10 F5000
As per 行# (straight and crossing) + 木 tree/wood → straight and crossing beams/girders → *beam*; *girder* → *rack for hanging kimono*; *abacus bar* → *digit/(numerical) placeholder*.
[Full Kanji Etymology List]